The deeper issue is whether this pattern is linked to the rapid changes that global warming is causing in the Arctic, particularly the drastic loss of sea ice. At least two prominent climate scientists have offered theories suggesting that it is. But others are doubtful, saying the recent events are unexceptional, or that more evidence over a longer period would be needed to establish a link.

Since satellites began tracking it in 1979, the ice on the Arctic Ocean’s surface in the bellwether month of September has declined by more than 30 percent. It is the most striking change in the terrain of the planet in recent decades, and a major question is whether it is starting to have an effect on broad weather patterns.

Ice reflects sunlight, and scientists say the loss of ice is causing the Arctic Ocean to absorb more heat in the summer. A handful of scientists point to that extra heat as a possible culprit in the recent harsh winters in Europe and the United States.

Their theories involve a fast-moving river of air called the jet stream that circles the Northern Hemisphere. Many winters, a strong pressure difference between the polar region and the middle latitudes channels the jet stream into a tight circle, or vortex, around the North Pole, effectively containing the frigid air at the top of the world.

[Update 2: 12/29/10 – Ed Rodgers of NJN TV does a story on NJ’s extreme weather – but State Climatologist Robinson, as usual, rejects global warming links and actually says it is NOT climate change (while speculating about La Nina), says “meteorology trumped climatology”. Robinson should talk to Dr. Cohen, who has a very different analysis]

The standard scientist answer is “you cannot blame a specific weather/climate event on global warming.” That answer, to the public, translates as “no”. However, if the question were posed as “would these events have occurred if atmospheric carbon dioxide had remained at its pre-industrial level of 280 [parts per million] ppm?”, an appropriate answer in that case is “almost certainly not.” That answer, to the public, translates as “yes”, i.e., humans probably bear a responsibility for the extreme event.

In either case, the scientist usually goes on to say something about probabilities and how those are changing because of global warming. But the extended discussion, to much of the public, is chatter. The initial answer is all important. Although either answer can be defended as “correct”, we suggest that leading with the standard caveat “you cannot blame” is misleading and allows a misinterpretation about the danger of increasing extreme events.

Our climate is changing, causing the world’s seas to rise. Since 1970, New York State has witnessed incrementally higher increases in average temperatures than the rest of the United States, an increase nearly twice the global average. These changes have resulted in warmer winters and hotter summers and other changes in the form of fewer, but heavier snows and heavier, more intense rainfall and storms. The warming produced by global climate change causes the sea level to rise because warmer water takes up more space and higher temperatures are melting ice sheets around the globe. New York Harbor has experienced an increase in sea level of more than 15 inches in the past 150 years, with harbor tide gauges showing a rise of between 4 and 6 inches since 1960.

Findings:

1. Sea level rise and coastal flooding from storm surge are already impacting and will increasingly affect New York’s entire ocean and estuarine coastline from Montauk Point to the Battery and up the Hudson River to the federal dam at Troy. New York must act now to address the challenge of sea level rise.

2. The likelihood that powerful storms will hit New York State’s coastline is very high, as is the associated threat to human life and coastal infrastructure. This vulnerability will increase in area and magnitude over time.

Many parts of New Jersey’s densely populated coast are highly vulnerable to the effects of flooding, storm surge, episodic erosion, chronic erosion, sea level rise, extra-tropical, and to a somewhat lesser albeit not at all unimportant degree, tropical storms. The risk to the State’s coast posed by each of these particular hazards is also likely to be complicated by anticipated changes in regional climate in the future. Hazards identified as a high level of risk have been so identified through historical experience and vulnerability to coastal hazards as documented within each countyâ€™s Multi-Hazard Mitigation Plan (produced in accordance with Federal Emergency Management Agency guidance under the Disaster Mitigation Act of 2000) and assessments produced by both the federal government and regional academic institutions.

New Jersey’s coastal area is comprised of a variety of different landscape types ranging from elevated headlands to wave-dominated and mixed-energy barrier islands to extensive mosaics of tidal and freshwater wetlands. Although each of these areas has evolved uniquely in response to their respective environmental conditions over many millennia, the entirety ofNew Jersey’s coastal area is subject to the damaging impact of coastal hazards including riverine and coastal flooding and gale-force winds from hurricanes, nor’Easters and extreme rain events. Although the scale, duration and seasonality of each of these coastal hazards varies by storm, the proximity of much of New Jersey’s coastal population and infrastructure to areas impacted by these hazards, as well as long-term hazards such as chronic erosion, has resulted in the potential for damaging consequences to the welfare of people and property during future storm events. This circumstance is exacerbated by long-term biophysical and climate trends which indicate that New Jersey will likely be subject to higher sea levels, an accompanying loss of natural coastal buffers (leading subsequently to more extensive overland storm surges and periodic inundation/flooding) as well as a trend toward stronger storm events, albeit occurring with greater irregularity and/or frequency. The sum consequence is the need for coastal managers and planners to accurately identify natural hazard risks and vulnerabilities throughout New Jersey’s coastal area in order to provide proactive guidance in planning and mitigating against potentially damaging future events.

A recent characterization of the anticipated coastal impact of sea level rise was produced by Princeton University researchers in 20051. The researchers created projections of future sea level rise based on a combination of a derivation of the combined sea level rise from global and local factors, yielding an estimated range of between .31 and 1.10 meters by the year 2100. The researchers then applied sea level rise inundation levels considered to be most likely (.71 meters, which, due to limits in data precision at the time, was approximated as .61 meter/2 feet) and highest end (1.10 meters, approximated to be 1.22 meter/4 feet) upon available state elevation data. The result was that 1 – 3% of New Jersey’s land area would likely be subject to permanent inundation by the end of the century. Projecting these same sea level rise estimates onto the base flood elevations of present special flood hazard areas, the researchers concluded that 6.5 – 9% of the State would thus be subject to special flood hazard area designation.